Molecular cloning, characterization and functional expression of the rat liver interleukin 6 receptor.

摘要: A series of cDNA clones coding for the rat liver interleukin 6 receptor (IL6-R) were isolated from an acute-phase library. The identity was established (a) by DNA sequence analysis and comparison with known human leukocyte IL6-R (b) demonstrating that generated specific IL6 ligand binding activity IL6-dependent regulation gene control elements after transfection into appropriate recipient cells. Two types obtained corresponding to two mRNA species different length, both encoding identical protein 462 amino acid residues. prototype clones, pRIL6RC.21 pRIL6RC.6 contained 3'-untranslated regions 550 3100 nucleotides, respectively. motifs TTATTTAT ATTTA associated stability translation efficiency present only in longer species. deduced 53% IL6-R. Both receptors conserved structural features their extracellular domains, including signal peptide, a C2 domain characteristic immunoglobulin superfamily, domains shared among members family cytokine growth factor receptors. strongly intracellular portion lacked recognizable transduction domains. used demonstrate concentrations increased 4.2-fold at 12 h induction experimental response. Clone pRIL6R.21ex, but not clone pRIL6RC.6ex, Jurkat cells lack endogenous By contrast, pRIL6RC.6ex reconstituted response Hep3B-2 HepG2 hepatoma mouse IL6. These highly responsive did respond physiologic murine After cotransfection plasmids containing chloramphenicol acetyltransferase reporter under plasma genes, these showed strong stimulation recombinant Thus, cell surface complete cascade terminating transcriptional promoters successfully reconstituted. Therefore, code functionally active receptor, depending on target cell, coded significant levels lines.